Hollow rib lath



Oct. 29, 1940. e. A. BUTTRESS HOLLOW RIB LATH Filed Aug. 4, 1938Patented Oct. 29, 1940 VUNITED STATES PATENT OFFICE to Buttress BoardCompany, Los Angelcs, Calif., a corporation of'California ApplicationAugust 4,

Claims.

This invention relates to lath and more particularly pertains to hollowrib sheet lath of the character set forth in my copending applicationfor United States Patent Ser. No. 137,960, filed 5 April '20, 1937, andalso set forth in United States Patent No. 2,077,513, issued April 20,1937; the

present invention more particularly pertaining to improvements in themetallic reinforcments of the hollow rib structure.

The primary object of the present invention is to provide a metallicreinforcement for the hollow ribs of the lath which is extremely lightin weight and of such form and character as to facilitate driving ofnails through the reinforced ribs and 18 whereby the resultant lathstructure will be more easily handled and applied.

Another object is to provide a construction in a metallic reinforcementwhich while affording adequate strength will involve the use of agreatly decreased amount of metal over the construction heretoforeemployed.

A further object is to provide a metal reinforced construction in thehollow rib of a sheet lath such as will permit adjacent lath panelsbeing mounted with their ends overlapped and overlapping end portionsreadily crushed and indented so that a body of plaster of adequatethickness may be applied over the overlapped end joint of the lath toobviate cracking of the plaster along said joint.

-With the foregoing objects in view, together with such other objectsand advantages as may subsequently appear, the invention is carried intoeffect as illustrated by way of example in the accompanying drawing, inwhich:

Fig. 1 is a view in elevation of the hollow rib sheet lath showing it asapplied;

Fig. 2 is a detail in section as seen on the line 2--2 of Fig. 1 in thedirection indicated by the arrows;

Fig. 3 is a view in elevation of a fragmentary portion of a metallicreinforcing strip showing it as detached;

Fig. 4 is a detail in section taken on the line 4-4 of Fig. 1 as seen inthe direction indicated by the arrows showing the manner of overlappingand crushing the ends of the sheet lath in forming the joint betweenadjacent panels thereof;

Fig. 5 is a detail in perspective of a fragmentary portion of the lathas seen from the back thereof with portions removed and depicting themetallic reinforcing strip in place.

Fig. 6 is an enlarged detail in section taken on the line 6-6 of Fig. 5.

Referring to the drawing more specifically, A

1938, Serial No. 223,060

indicates generally a corrugated facing sheet formed of flexible fibrousmaterial such as paper, pulp board or the like, and is preferably ofmoisture'absorptive character throughout. The corrugations of the sheetA are of substantially 5 dove-tail cross section and are formed toprovide relatively wide hollow ribs 1 and relatively narrow dove-tailchannels 8 between adjacent of the ribs.

The corrugated sheet A is affixed to a backing 10 sheet B preferablyformed of a flexible fibrous material such as paper and which ispreferably treated to be fire-resistant and moisture proof; the sheet Abeing affixed to the backing sheet B by adhering the bottom walls of thechannels 15 8 to the backing sheet by means of a suitable adhesive.

In carrying out the present invention the inner surfaces of the hollowribs 1 are coated with a layer!) of plastic cementitious material whichis 20 of moisture resistant character, such as asphaltum, that has beentreated to render it fire resistant.

Partially imbedded in the layer 9 is a metallic reinforcing strip Cwhich embodies a pair of 5 wires l0 apart so as to form-a series oftrans- 1 versely triangular webs b as particularly shown in Figs. 3 and5. Y

In order to avoid stretching of the webbing, transverse slits c areformed between the contiguous longitudinal webs b which slits permitspreading of the web b laterally of the strip to any desired distancewithin the length of the diagonal marginal portions of the web. In thusspreading the marginal wires H] to form the Webbing II the metal stripsconstituting the 5 webbing are bent to lie in angular relation to theplane of the reinforcing strip as particularly shown in Figs. 2 and 6,thus presenting the webbing substantially edge-wise to the outer wallsof the rib I and thereby rendering the webbing quite resistant tobending inwardly under pressures imposed on the outer faces of the lathrib.

The marginal wires H] of the reinforcing strip C are spaced apart suchdistance as to snugly nest in the acute angle formed interiorally of themarginal portions of the ribs 1 such that the side walls :1 of the ribsand channels will aid in anchoring and holding the reinforcing strip Cin position against the outer wall of the ribs. The margins of the wiresII] are spaced from the backing sheet B so as to render the side walls:2 of the ribs and channels subject to being readily collapsed at theends of the ribs on applying the sheet lath to a supporting structure,as will presently be described.

By forming the reinforcing strips C as herein set forth the open webbingb renders the strip quite foraminous such as to readily permit drivingof nails through the ribs I.

In applying the sheet lath to its supporting structure, such as studdingD, as shown in Fig. 1, panels of the lath of suitable dimensions areapplied to the studding and secured thereto .by nails l2 which latterare driven through the ribs 1. In order to avoid a crack between theends of adjacent lath panels, as is likely to occur where the sheetpanels are abutted end to end, the end portions of .the adjacent panelsare overlapped with the end portions of the ribs thereof in longitudinalalignment with each other. A nail 1-2 is then driven through each riband the overlying end portions of theribsarepoundeddown so as to.collapse of the side walls 11 thereof as shown in Fig. 4, and wherebythe overlapping end portions of the panels may be formedtoextendsubstantiallyfiush with or be indented relative to the plane of thefront face of the assembled panels, so that when a body of plaster E isapplied over the jointsuch plaster will have a thickness equal to if not5 slightly exceeding the thickness of the plaster protruding in front ofthe faces of the ribs 1 intermediate the ends of the panels, thusobviating subsequent cracking of the plaster along the joints betweenends of adjacent lath panels as sometimes occurs where lath panels areabutted at their ends.

The foraminous structure of the metal :reinforcing strip C permits thelatter being crushed down at the overlapping joints at the ends'of thelath panels without placing the reinforcing strips under tension.

By expanding the metal of the reinforcing strip as herein set forth aconsiderable reduction in the amount of metal required to form the stripis effected over that required where the strip is formed of a ribbon-ofmetal of the width of the rib I, thus effecting an economy in metal andalso decreasing the weight of the lath panel, and yet affording adequatestrength for light construction purposes.

While I have shown and described a specific embodiment of my invention Ido not limit myself to the exact details of construction set forth, andthe invention embraces such changes, modifications and equivalents ofthe parts and their formation and arrangement as come within the purviewof the appended claims.

I claim:

1. In a hollow ribbed sheet lath, embodying a corrugated facing sheetformed to provide hollow ribs and channels of dove-tailed cross section,a backing sheet, and a metallic reinforcing strip interiorally of saidhollow strip, said strip embodying spaced marginal wires of angularcross section, an open webbing interconnecting said wires, and acementitious material on the inner wall of said ribs in which thewebbing of said reinforcing "strip is partially imbedded.

2. In a hollow ribbed lath, a backing sheet, a fibrous corrugated facingsheet formed with ribs and channels, said ribs being hollow, a layer ofplastic material adhered to the inner face of the outer wall 'of saidribs and a foraminous metallic reinforcing strip at least partiallyimbedded in said plastic material. 3. In a hollow ribbed lath, a backingsheet, a fibrous corrugated facing sheet formed withribs and :channelsof dove-tailed cross section, said ribs being hollow, a layer of plasticmaterial adhered to the inner face of the outer wall of said ribs and aforaminous metallic reinforcing strip at least partially embedded insaid plastic material, said strip having continuous marginal wiresextending contiguous the side walls of said channel.

4. In a hollow ribbed lath, a backing sheet, a fibrous .corrugatedfacing sheet formed with ribs and channels of dove-tailed cross section,said ribs being hollow, a layer of plastic material adhered to the innerface of the outer wall of said ribs and .a foraminous metallicreinforcing strip at least partially imbedded in said plastic material,saidcstrip-having continuous marginal wires extending contiguous theside Walls of said channel, said reinforcing strip being formed of sheetmetal with the wire margins thereof of angular cross section, and with awebbing interconnecting said wire margins the marginalportions of whichextend in angular relation to the plane of the face-of the reinforcingstrip.

5. Ina hollow ribbed lath, a corrugated facing sheet of flexible fibrousmaterial the ribs and channels of which are of dove-tailed crosssection, a backing sheet to which the facing sheet is afiixed, spacedmetallic wires extending longitudinally of said ribs interiorallythereof and seating in the acute angle formed at the intersection of theside walls and the outer wall portion of the dove-tailed ribs, andplastic means holding said wires in place.

GEORGE A. BU'I'I'RESS.

